Journal
CIRCULATION
Volume 128, Issue 6, Pages 598-604Publisher
LIPPINCOTT WILLIAMS & WILKINS
DOI: 10.1161/CIRCULATIONAHA.113.002937
Keywords
cocaine; echocardiography; microcirculation; myocardial perfusion imaging
Funding
- National Institutes of Health (NIH) [R01DA10064]
- Lincy Foundation
- NIH/National Center for Advancing Translational Sciences UCLA CTSI [UL1TR000124]
- Heart and Stroke Foundation of Canada
Ask authors/readers for more resources
Background Cocaine is a major cause of acute coronary syndrome, especially in young adults; however, the mechanistic underpinning of cocaine-induced acute coronary syndrome remains limited. Previous studies in animals and in patients undergoing cardiac catheterization suggest that cocaine constricts coronary microvessels, yet direct evidence is lacking. Methods and Results We used myocardial contrast echocardiography to test the hypothesis that cocaine causes vasoconstriction in the human coronary microcirculation. Measurements were performed at baseline and after a low, nonintoxicating dose of intranasal cocaine (2 mg/kg) in 10 healthy cocaine-naive young men (median age, 32 years). Postdestruction time-intensity myocardial contrast echocardiography kinetic data were fit to the equation y=A(1-e(-t)) to quantify functional capillary blood volume (A), microvascular flow velocity (), and myocardial perfusion (Ax). Heart rate, mean arterial pressure, and left ventricular work (2-dimensional echocardiography) were measured before and 45 minutes after cocaine. Cocaine increased mean arterial pressure (by 14 +/- 2 mm Hg [mean +/- SE]), heart rate (by 8 +/- 3 bpm), and left ventricular work (by 50 +/- 18 mm HgmL(-1)bpm(-1)). Despite the increases in these determinants of myocardial oxygen demand, myocardial perfusion decreased by 30% (103.7 +/- 9.8 to 75.9 +/- 10.8 arbitrary units [AU]/s; P<0.01) mainly as a result of decreased capillary blood volume (133.9 +/- 5.1 to 111.7 +/- 7.7 AU; P<0.05) with no significant change in microvascular flow velocity (0.8 +/- 0.1 to 0.7 +/- 0.1 AU). Conclusions In healthy cocaine-naive young adults, a low-dose cocaine challenge evokes a sizeable decrease in myocardial perfusion. Moreover, the predominant effect is to decrease myocardial capillary blood volume rather than microvascular flow velocity, suggesting a specific action of cocaine to constrict terminal feed arteries.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available